S-acyl derivatives of 3-mercapto-2-chloroproopyl n,n-dialkylthiolcarbamates

ABSTRACT

Undesired vegetation, particularly noxious grasses in growing crops, are combated by pre-emergent application of selective herbicides made by reacting an organic compound having a reactive halogen substituent with a 2,3-epithiopropyl N,Ndialkylthiolcarbamate to yield a compound of the structural formula   IN WHICH R and R&#39;&#39; represent hydrocarbon substituents containing less than 10 carbon atoms, X is halogen, preferably bromine or chlorine and Y may be alkanoyl, chloroalkanoyl, bromoalkanoyl, alkoxyalkanoyl, N,N-dialkylcarbamyl, carbalkoxycarbonyl, alkoxymethyl, alkoxyethyl, chlorobenzoyl, bromobenzoyl, chlorophenoxyacetyl, bromophenoxyacetal, cyclopropylcarbonyl, cyano, methanesulfonyl, alkanoylmethyl alkylmercaptomethyl, nitrobenzoyl, chlorocarbalkoxyl, bromocarbalkoxyl, ethynylmethyl, dialkylphosphono, dialkylthiophosphono or alkylmercaptocarbonyl, said alkanoyl, alkoxy, carbalkoxy and alkyl structures containing less than 10 carbon atoms.

Writ tates Patent [1 1 Doyle,,fir.

[ S-ACYL DE 1" 1 ATIVES 0F 3- MERCO-Z-CHLOROPROOPYL N,N- DHALKYILTHIOLCARBAMATES [75] Inventor: William Carter Doyle, Jr., Leawood,

Kans.

[73] Assignee: Gulf Research & Development Company, Pittsburgh, Pa.

[60] Division of Ser. No. 851,432, Aug. 19, 1969, Pat. No. 3,628,945, which is a continuation-in-part of Ser. No. 625,603, March 24, 1967, Pat. No. 3,510,290.

[52] US. Cl. ..260/455 A, 260/327 E, 260/455 R [51] Int. Cl ..C07c 155/08 [58] Field of Search ..260/455 A, 455 R, 327 E; 71/100 [56] References Cited UNITED STATES PATENTS 3,247,225 4/ 1966 Fields et al. ..260/455 A 3,318,676 5/1967 Harman et 3,342,835 9/1967 Lies 3,407,222 10/1968 Lies 2,918,476 12/ 1959 Queen ..260/327 E FOREIGN PATENTS OR APPLICATIONS 810,389 3/1959 Great Britain ..260/455 R 886,425 1/ 1962 Great Britain ..260/455 A OTHER PUBLICATIONS Epshtein et al., Haloalkyl Sulfides, etc., (1963) CA60 pp. 7909-7910 (1964) Sander, Thiiranes (1965) Chem. Rev. 66 pp. 297-339 (1966) Tilles, Thialcarbamates Prep. & Molar Refractions (1958) JACS 81 pp. 714727 (1959) Primary Examiner-James 0. Thomas, Jr. Assistant Examiner-G. Hollrah Attorney-C. A. Cline ABSTRACT Undesired vegetation, particularly noxious grasses in growing crops, are combated by pre-emergent application of selective herbicides made by reacting an organic compound having a reactive halogen substituent with a 2,3-epithiopropyl N,N-dialkylthiolcarbamate to yield a compound of the structural formula R O X in which R and R represent hydrocarbon substituents containing less than 10 carbon atoms, X is halogen, preferably bromine or chlorine and Y may be al- 8 Claims, No Drawings S-ACYL DERIVATIVES OF 3-MERCAI'TO-2- @ll-llLOlROPROOPYL N,N- DIALIKYLTHIOLCARBAMATES DESCRIPTION OF THE INVENTION II: was disclosed in the prior application that both II and Ill can be reacted with acetyl chloride to yield products which have identical NMR spectra and it was postulated that both products are the same compound hav-.

ing the following structural formula:

It has now been discovered that compounds of the type represented by structural formula III may be reacted with organic compounds having reactive halogen substituents to yield a new class of selective herbicides having the generic structural formula:

in which R and R represent hydrocarbon substituents containing less than carbon atoms, X is halogen, preferably bromine or chlorine and Y may be alkanoyl, chloroallcanoyl, bromoalkanoyl, alkoxyalkanoyl, N, N- dialkylcarbamyl, carbalkoxycarbonyl, alkoxymethyl,

alkoxyethyl, halobenzoyl, halophenoxyacetyl, cyclopropylcarbonyl, cyano, methanesulfonyl, alkanoylmethyl, alkylmercaptomethyl, nitrobenzoyl,

halocarbalkoxyh, ethynylmethyl, dialkylphosphono, dialkylthiophosphono or alkylmercaptocarbonyl, said alkanoyl, alkyl, alkoxy and carbalkoxy groups containing less than 10 carbon atoms.

A great deal of variation is possible in the Y substituent of the above general formula, so as to vary the physical and biochemical properties of the new class of herbicides. In the discussion below there are presented data which show variation in phytotoxicity ranging from pre-emergent action selective to one or two particular grasses to broad activity, both post and preemergent, toward many species, with relatively less activity toward a small number of crops. The critical factor in successful preparation of this class of herbicides appears to be the use of an organohalogen compound having a sufficiently reactive halogen-to-carbon bond. This puts practical limits on choice of the Y groups, which, of course, is the organic nucleus to which the reactive halogen is attached.

Active halogen compounds which may be used include cyanogen halides, alkanesulfonyl halides, alphahaloethers, propargyl halides, alpha-haloketones and halothioethers, acid halides of both aliphatic and aromatic carboxylic acids.

I Discussion of Method of Synthesis of the Herbicides Below are presented suggested procedures for synthesis of the epithiopropyl N,N-dialkyl-thiolcarbamates, as well as illustrative procedures for preparation of the herbicides of this invention by reaction with active halogen compounds.

The 2,3-epithiopropyl N,N-dialkylthiolcarbamates may be prepared by two general methods, one a threestep process, with isolation of intermediates and the other essentially a single-step process, as illustrated below: METHOD A III II The initial low temperature reaction is believed to include reaction of epichlorohydrin with N,N-dialkyldithiocarbamic acid.

III

The reaction of epichlorohydrin with a salt (which may also be a metal salt, as well as an amine salt) appears to require a higher temperature than reaction with the acid.

In an experiment in which both routes were used to prepare the same N,N-diethyl thiolcarbamate compound, the yields were roughly equivalent. In syntheses based on morpholine, dicyclohexylamine or isopropyl cyclohexylamine as starting materials, Method B has been found to be the only successful route, with the dithiocarbamate salt being the sole product obtained in the first step of Method A, rather than the more reactive free acid.

Intermediates (l) and (II) are capable of isolation but are not easily purified. Compound (I) is thermally unstable, rearranging to (II) in a a matter of several hours to several days, depending on the nature of the N substituents. The structure of (I) is thought to be as shown, based on its infrared spectrum and the NMR spectrum of its phenylurethane derivative. Intermediate compounds (II) are relatively stable and suitable for use in manufacturing the herbicides of this invention, although use of the more stable epithiopropyl compounds (III) is preferred. Present evidence favors the structure of II shown in the reaction diagram below, which shows schematically the treatment with acetyl chloride of both compounds (II) and (III) to give compounds of type (IV).

RN l \viiscmtirrcmsn N( JSCHiCH-CH2 III CH C 0 Cl 0 01 o Nt iscmcnomsbcm The 3-substituted-Z-halopropyl thiolcarbamates as illustrated by (IV) above are generally liquids at room temperature and are stable in storage, but resemble compounds of type (III) in sensitivity to heating.

II Illustrative Procedures Method A To a well-stirred mixture of 38.0 g. (0.5 mol) of carbon disulfide and 46.3 g. (0.5 mol) of epichlorohydrin in an ice-salt bath is added 36.5 g. (0.5 mol) of anhydrous diethylamine during 1 2 hours at 0 to -5C. The mixture is stirred an additional 30 minutes, then let warm slowly to room temperature. At this point the reaction mixture is essentially 3-chloro-2-hydroxypropyl N,N-diethyldithiocarbamate, (I; R,R'=Et), a viscous yellow oil with no detectable unreacted starting materials present.

Heating of the reaction mixture for 2 hours at under vacuum gives 1 10 g. of crude rearrangement product II (R,R'=Et). The course of the rearrangement may be easily followed by the disappearance of infrared absorption bands at 2.95 p. (OH) and 10.15;]. (C=S) and with the appearance of bands at 3.92p. (SH) and 60p. (C=O). The rearrangement is also accompanied by a marked decrease in viscosity.

To 29 g. (0.12 mole of the crude rearranged product in ml. of ether is added slowly 12 g. (0.12 mols) of triethylamine. Reaction is immediate, causing the ether to reflux gently and precipitating 10.8 g. of triethylamine hydrochloride. The solution is filtered, evaporated and vacuum distilled, giving 15.1 g. (61.4 percent yield overall) of 2,3-epithiopropyl N,N- diethylthiolcarbamate (III; R,R=Et), b.p. 1 1920Method B A solution of 36 g. (0.173 mol) of diethylammonium diethyldithiocarbamate and 15.0 g. (0.162 mols) of epichlorohydrin in 100 ml. of dioxane is heated to reflux. Shortly after heating is begun, a crystalline precipitate appears. After 2 hours, the solution is cooled and filtered to recover 15.4 g. of diethylamine hydrochloride. The filtrate is vacuum distilled to remove the bulk of the solvent, leaving 33.2 g. of a viscous brown oil. Extraction of this oil with ether, decantation and evaporation of the ether gives 25.7 g. of residue, distillation of which gives 17.7 g. of a compound of type (III) in which R and R are ethyl.

The procedures illustrated may be used with various secondary amines or dithiocarbamates as starting materials to produce the desired epithiopropyl thiocarbamates, Method A being generally more desirable because it employs cheaper raw materials and generally gives good yields. Below are presented illustrative examples of syntheses of 3-organothio-2-halopropyl N,N- di-substituted thiolcarbamates of this invention.

Preparation of 3-acetylthio-2-chloropropyl N,N-diethyl thiolcarbamate s o H EtQNCSCH1CH--CH 0H3001 II 1 EnNosomcncmsccin A mixture of 16.4 g (0.08 mole) of 2,3-epithiopropyl N,N-diethylthiolcarbamate and 6.3 g (0.08 mole) of acetyl chloride is heated 5.5 hours on the steam bath under reflux and then distilled at reduced pressure. Following a short fore-run, there is obtained 3.4 g of an intermediate cut, b.p. 133140 at 0.07 mm and 10.8 g of 3-acetylthio-2-chloropropyl N,N-diethylthiolcarbamate, b.p. 140-5 at 0.05 mm, N26,,

Preparation of 3-cyclopropanecarbonylthio-2- chloropropyl N,N-diethylthiolcarbamate A mixture of 10.3 g (0.05 mole) of 2,3-epithiopropyl N,N-diethylthiolcarbamate and 5.2 g (0.05 mole) of cyclopropanecarbonyl chloride is heated 20 hours on the steam bath and then vacuum stripped at C. pot temperature and 0.1 mm pressure giving as the residual oil, 14.2 g of 3-cyclopropanecarbonylthio-2- 3,723,493 5 6 chioropropylN,N-diethylthiolcarbamate,N26 Preparation of 3-methoxymethylthio-Z-chloropropyl Preparation of 3-thiocyano-2-brom0propyl N,N- N.N- p py i Dipropylthiolcarbamate A miXtlll'e f g 111018) of p pr0pyl A mixture of 23.3 g (0.1 mol) of 2,3-epithiopropyl N.N-dipr0pylthi01arbamate and g 0f 10 N,N-dipropylthiolcarbamate and 8.1 g (0.1 mol) of cyanogen bromide is heated four hours on the steam chloromethyl methyl ether is heated 2 hours at 60 bath and then dissolved in 100 ml Of benzene. Addition under a reflux condenser and then vacuum stripped at of 200 ml of hexane precipitates a small amount of 100 pot temperature and 0.1 mm pressure to give 30.5 gummy solid. Filtration of the benzene-hexane solution g of 3-methoxymethylthio-Z-chloropropyl N,N- and evaporation at reduced pressure leaves 11.4 g of 15 dipropylthiolcarbamate,

viscous residual oil, shown by its NMR spectrum to be Tabulated below are chemical and physical properprimarily 3-thiocyano-2-bromopropyl N,N- ties of specific products obtained by the procedures dipropylthiolcarbamate. discussed and illustrated above.

. A w milbl Properties of Products of Formula RRNC0SCHzCXHCH2S-Y Analysis R and ND/ C. 01 Calcyd Found Compound No. R x- Y B.P. mm'. (J 11 N X c H N X cli 30Hc11 c1-i :cH1C1 3 nC3H7 0 1.5338/23 34.71 4.01 3.38 34.16 35.77 4.55 3.42 33.48

Oll JCCla Cl-CA Cl-( ltC4H Cl- J-CHzC(CH1)4 7 .nC;H7 0 1.5153/24. 49.46 7.71 4.12 10.43 49.55 7.00 3 0.35

Cl-i 3ls0CaH c1-i 3-c112-G112G1 c1d.cH1c11,coc115 01-H1-01n0om Br-i cH,Br

Clg}4ClC5I-I5 (xii-00112011201 c1 s011 c1 4 Cl-i 3-N(C H v Cl-QJ-OOCzHs C1-iiP-CH:

Ckda

Properties of Products of Formula RRNCOSCH2CXHCHzS-Y Analysis Calcd Found Compound N0. R'and Y 1 31 1 7511? H N x c H N C1( 3NOz C1HICH3 22 nC3H1 O 1.5203/24 46.20 7.06 4.40 46.91 7.22 4.75 V

Cl 1CHa 23 nC H OCHs ICl 1.5590/24 46.72 5.12 2.96 46.30 5.00 3,35

ClC

24 nG5H1 0 (I31 1.5602/23 45.72 5.12 2.96 22.49 45.94 5.19 2.91 21.3

Cl( J-CHzO C1 25 n-C.-1H1 0 C1 C1 1.5660/24 40.41 5.12 3.39 34.33 43.80 4.30 3.28 31.25

26 .n-C:H1 O 1-5176/25 47.90 7.42 4.30 10.88 48.18 7.60 4.27 10.53

Cl J-CzHa 27 ..I1-C:1H7 0 1.5108/25 50-90 7.97 3.96 10.02 46.18 8.25 3.71 9.35

O1( 3-n-C Hn 28 r1-C H7 O 1.5151/25 49.46 7.71 4.12 10.43 49.37 7.99 4.04 10.49

O1( Jn-CaH7 v 29 n-CaH1 O 1.5016/24 54.58 6.65 3.54 8.95 56.79 8.85 3.68 8.80

O1-( ]n-C H15 30 n-C5H1 O 1.5212/24 43.33 6.43 3.89 19.68 43.35 6.67 4.06 19.99

CI-( JCHCH3 31 "Kl-C3117 O 1.5132/25 50.90 7.97 3.96 10.02 51.23 8.38 3.88 10.24

Cl-( 1isoC4Ho Cl4 3C H5 33 is0C3H7 O 1.5152/25 49.46 7.71 4.12 10.43 49.46 8.19 4.24 10.16

C14 3n-C H1 34 .1'S0C3H7 O 1.5100/25 49.46 7. 71 4.12 10.43 49.95 7.95 3.07 0.85

Cl4 ]isoCaH1 C1-4 3t-C Ho C1 H n-C Hn 37 4 is0C 1I1 O 1.54 3/25 50.00 7. 7 3.96 10.0 51.18 8.18 4,05 10,30

Cl- -1s0C H9 3g ..isoC;H (I? 1.5213/25 41.48 6.16 3.72 18.84 43.95 6.70 5.35 14.4

C1C-OCH;CH;C1

39 isoC H1 O 1.5215/25 45.66 7.08 4.10 10.37 47.88 7.39 4.00 0.69

C1 CH OCH 40 1SOC3H7 1. 5129/25 5-58 6.28 3.80 9.61 45.63 6.80 4.05 10.03

Analysis R and ND C. or Calcd Found Compound No. R X Y B.P./mm. C H N X C H N X 4 18003111 1. 6257/25 43. e1 6. 7s a. 91 9. 91 47. 69 7. 45 7 80 9, 4

o1( i s 02H.

42 1500.111 1. 5365/25 34. 11 4. 61 a. as 34. 1e 3e. 31 5. 09 3. 44 32,

43 iSOCaH7 0 H CH C H, 1. 5006/ 52. 22 3. 22 3.81 9. 64 52. 55 8.10 3. 84. 9. 75

1. 4959/26 41. 55 5. 52 4. 04 21. 18 38. 52 5. O8 5. 40 19. 55 o1-do F2 01 2 82 1111;111:111: 2213?. E1231 $333 2512? .3133. Z22? $322 131%? C1-S OZCHT! 1. 5398/24 38. U1 6. 33 4. 03 i 10. 21 45. 4O 7. 43 5. 77 8. 10 C1 S O2nC;1H 1. 5276/25 41. 52 6. 97 3. 72 9. 43 41. 74 7. 14 3. 81 8. 53

1. 5245/26 47. 91 7. 42 4. v 10 88 48. 7. 47 4. 24 10. 73 Cl-CH2("3 CH2 BI-CHQC 5 CH: 1. 5452/27 44. 3O 6. 29 3. 85 22. 67 46. 06 6. 93 3. 88 18. 20 ClCHg S CH 1. 5385/26 52. 29 8. 71 5. 08 12. 86 46. 33 7. 73 11. 05 7. 3O

0 1. 5229/26 41. 42 7. 2o 3. 45 s. 73 46. as 7. s9 6. 95 s. 72 01-4 0 Et):

S 1. 5130/26 39. S4 6. 93 3. 32 7. 34 42. 32 7. 61 4. 59 7. 68 (ll-i" (0131:) 1

Ill. Herbicidal Use A. Post Emergent Activity An aqueous dispersion of each active compound was prepared by combining 0.4 gram of the compound with about 4 ml. of a solvent-emulsifier mixture (3 parts of a commercial polyoxyethylated vegetable oil emulsifier, one part xylene, one part kerosene) and then adding water, with stirring, to a final volume of 40 ml.

The species of plants on which each compound was to be tested were planted in 4 inch pots in a greenhouse. Ten to 18 days after emergence of the plants, three pots were sprayed with an aqueous dispersion of the active compound prepared as described above, at a rate of 5 lb. of active compound per acre and at a spray volume of gallons per acre. Approximately one week after the spray application the plants were observed and the results rated according to the following schedule:

Herbicidal Effect 0 no effect 1 slight effect 2 moderate effect TABLE 2 3 severe effect 4 maximum effect (all plants died) The same rating schedule was employed to judge pre-emergent results obtained according to the procedure below.

B. Pre-emergent Activity A solution of each active compound was prepared by dissolving 290 mg. of the compound to be tested in 200 ml. of acetone. Disposable paper half-flats (molded pulp trays about 2 to 3 inches deep and half the size of ordinary greenhouse flats) were prepared and seeded with a variety of species of plant seeds, then sprayed with the acetone solution at the rate of 10 lb. of active chemical per acre of sprayed area. One flat, which has been seeded with alfalfa, brome, flax, oats, radishes and sugar beets were held at F. day temperature; another seeded with corn, coxcomb, cotton, crabgrass, millet and soybeans was held at F. Twenty-one days after seeding and treatment the flats were examined and herbicidal effect was rated according to the above schedule.

Both post-emergent and pre-emergent results are set forth in the following table.

Preand Post-Emergent Herblcidal Activity Grain Compound Crab- Cox- Soy- Cot- Al- Rad- Sugar so!- No. Type grass comb Brome Millet bran ton lalfn Oats Corn Flax isli be Wheat. ghum Tomato 1 {Pre 2 0 4 1 0 0 0 3 0 0 t) 0 Post. 0 2 0 0 0 1 0 0 0 0 U (l 2 {PI. 1 0 4 2 1 1 O 2 0 t) l) 1 Post.. 1 0 1 0 0 0 1 1 1 0 0 l 3 {Pre 3 2 4 4 2 1 1 4 0 1 3 1 Post". 0 0 0 0 O 0 0 O 0 0 0 0 4 {Pre.... 4 4 4 2 1 2 0 4 0 0 0 0 P051.... 0 0 0 0 0 0 0 0 0 0 0 0 5 {Pre 2 0 4 2 0 O 0 3 0 0 0 0 G rain Al- Rad- Sugar sorfalfa Oats Corn Flax ish beet Wheat ghum Tomato TABLE 2-Cominued Crab- Cox- Soy Cot- Type grass comb Bromc Millet bean ton Com pound No.

0 0 0 0 .0 .0 .0 0 0 l 0 0 0 4 4 4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 n 0 0 0 0 0 0 0 0 0 0 n u 1 .0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 .1 .2 .0 .0 0 .0 .0 .0 .0 0 0 .0 .0 .0 0 0 0 0 l n u n u H n u U u U H 0 h u u u u h H h H n U n U u n H n U U u u u u 000.0010000020000000.00001000001100 44443000010000000001000000010100000002000 000000 0000010001000 303o9-OJ00-01O9-0 09-01n 0 n1020102130424330209-02030303020202020 0 .1 .4 A 2 A "4 m4 m4. m4 4 m4 m4 "4 4 4 3 4 4 A 4 0 .0 0 0 .3 0 0 2 .1 .4 .4 4 .1 .1 .1 .1 1 1 0 1 1 0 1 U .1 .2 .1 .1 .4. .4 .4. A. .3 ded.. lmmnnhaeededtamaededun NWO 0H OfOfOr. or 0r. 0... 0r0r. or or O PPPPPP PPPPPPPPPPPPPPPPPPPPP 3-propanoylthio-2-ch1oropropyl dipropylthiolcarbam ate.

4. 3-propanoy1thio-2-chloropropyl N-N- diisopropylthiolcarbamate. I

5. 3-isovalerylthio-2-chloropropyl I claim:

1. 3-cyclopr0panecarbonylthio-Z-chloropropyl N,N- diisopropylthiolcarbamate.

2. 3-isobutyrylthio-2-ch1oropropyl dipropylthiolcarbamate.

diisopropylthiolcarbamate.

3-isobutyrylthio-2-chloropropyl diisopropylthiolcarbamate.

3-trichloroacetylthio-2-chloropropyl diisopropylthiolcarbamate.

diisopropylthiolcarbamate. 

2. 3-isobutyrylthio-2-chloropropyl N-N-dipropylthiolcarbamate.
 3. 3-propanoylthio-2-chloropropyl N,N-dipropylthiolcarbamate.
 4. 3-propanoylthio-2-chloropropyl N,N-diisopropylthiolcarbamate.
 5. 3-isovalerylthio-2-chloropropyl N,N-diisopropylthiolcarbamate.
 6. 3-isobutyrylthio-2-chloropropyl N,N-Diisopropylthiolcarbamate.
 7. 3-trichloroacetylthio-2-chloropropyl N,N-diisopropylthiolcarbamate.
 8. 3-butyrylthio-2-chloropropyl N,N-diisopropylthiolcarbamate. 